Description
In the Linux kernel, the following vulnerability has been resolved:

serial: 8250_dma: Clear stale RX state on shutdown

serial8250_release_dma() terminates RX DMA and releases the channel, but
leaves rx_running set. If the port is closed while an RX transfer is
active, the stale state remains while rxchan is NULL until the channel is
requested again on the next open.

The DesignWare BUSY workaround added by commit a7b9ce39fbe4
("serial: 8250_dw: Ensure BUSY is deasserted") calls
serial8250_rx_dma_flush() from the LCR write path during startup. This
happens before serial8250_request_dma() obtains a new RX channel. On
reopen, the stale rx_running state therefore makes the flush path pass a
NULL channel to dmaengine_pause(), causing a kernel Oops.

Clear rx_running after terminating RX DMA, matching the TX cleanup. Also
make the flush helper return if the DMA object or RX channel is not
available so startup and teardown paths cannot pass a NULL channel to the
DMAengine API.
Published: 2026-08-22
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Sat, 22 Aug 2026 15:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: serial: 8250_dma: Clear stale RX state on shutdown serial8250_release_dma() terminates RX DMA and releases the channel, but leaves rx_running set. If the port is closed while an RX transfer is active, the stale state remains while rxchan is NULL until the channel is requested again on the next open. The DesignWare BUSY workaround added by commit a7b9ce39fbe4 ("serial: 8250_dw: Ensure BUSY is deasserted") calls serial8250_rx_dma_flush() from the LCR write path during startup. This happens before serial8250_request_dma() obtains a new RX channel. On reopen, the stale rx_running state therefore makes the flush path pass a NULL channel to dmaengine_pause(), causing a kernel Oops. Clear rx_running after terminating RX DMA, matching the TX cleanup. Also make the flush helper return if the DMA object or RX channel is not available so startup and teardown paths cannot pass a NULL channel to the DMAengine API.
Title serial: 8250_dma: Clear stale RX state on shutdown
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-22T15:32:29.263Z

Reserved: 2026-08-15T05:44:03.923Z

Link: CVE-2026-74654

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-22T16:16:38.937

Modified: 2026-08-22T16:16:38.937

Link: CVE-2026-74654

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.